"I met Teddy the night I cut 'Stitches' and we’ve had a really special connection ever since then, and for her to feel so comfortable with me and the other songwriters the night she came out… I can’t express how happy that made me," he says. "And it’s something I really love to say: it’s a very new thing, right? People transitioning, there are still a lot of people who don’t understand it, and to refer to somebody as a pronoun that you haven’t been referring to them as their entire life, your entire life, is very difficult. But the thing that’s amazing is that I remember the day I said 'she,' and it wasn’t because I said it consciously, it was because I said it without thinking, basically just in conversation. I didn’t realize I did it, but she looked at me and she had the most incredible look in her eyes."

Mendes adds the exchange completely informed the way he now approaches social interactions.

"If every person in the world had one of their best friends look at them that way, and express that much joy in what it meant for her to be referred to as the pronoun she is, there would no longer be an argument [over trans rights]," he said. "People would just understand. It’s so powerful to have somebody you’re so close to go through something like that. It’s just f------ beautiful, man. I really wish you could have seen it."